Abstract:
The European Diatom Database (EDDI) is a web-based information system designed to enhance the application of diatom analysis to problems of surface water acidification, eutrophication and climate change.

The original dataset included 31 ponds and pools from southeast England. They are all relatively small, shallow, lowland, artificial waterbodies. All sites have circumneutral to alkaline pH and ... are nutrient-rich. Surface sediment samples were collected during July and August 1990 by University College London and diatoms were counted by Helen Bennion. Following removal of one outlier, a training set of the remaining 30 ponds was used to generate a diatom TP transfer function (Bennion, 1994, 1995; Bennion & Smith, 2000; Bennion et al., 1997). The diatom inference model had good predictive power (apparent r2=0.79; RMSE=0.161 log10TP µg l-1; RMSEP=0.279 log10TP µg l-1). A subset of 26 of these sites is included in EDDI and this forms part of the larger combined NW European training set (Bennion et al., 1996). Palaeolimnological studies have been undertaken at a number of the southeast England sites (Bennion, 1993, 1994).

Bennion, H. & Smith, M. A. (2000). Variability in the water chemistry of ponds in south-east England, with special reference to the seasonality of nutrients and implications for modelling trophic status. Hydrobiologia, 436, 145-158.